Wiimote hacked to create a multitouch display on almost any surface!

Thanks to Marc Avery for the link.
Awesome idea, great youtube video.
Via gearlog:

Using a Nintendo Wii remote and some software that he ginned up himself, Johnny Chung Lee of Carnegie Mellon University took a few ballpoint pens, replaced them with IR lights, and presto! Since the Wii tracks IR lights, Lee found that practically any surface -- a projector screen, a tabletop, an LCD screen -- could be turned into a multi-touch screen.

You can download Johnny's software at his website.
The video is here.